2-Fluorocyclohexene derivatives

ABSTRACT

2-Fluorocyclohexene derivatives of formula I ##STR1## where R, A 1 , Z 1 , X, L 1 , L 2 , m and n are as defined herein, and their use as components of liquid-crystalline media for electro-optical display elements, in particular for matrix liquid-crystal displays.

This application is a 371 of PCT/EP94/02546 filed Aug. 1, 1994.

This application is a 371 of PCT/EP94/02546 filed Aug. 1, 1994.

The present invention relates to 2-fluorocyclohexene derivatives of theformula I ##STR2## where R is an alkyl or alkenyl radical having up to18 carbon atoms which is unsubstituted or substituted by CN or by atleast one halogen and in which one or more non-adjacent CH₂ groups canbe replaced by a radical selected from the group consisting of --O--,--S--, --CO--, --O--CO--, --CO--O-- and --C.tbd.C--,

A¹

a) is a 1,4-phenylene radical, in which one or two CH groups can bereplaced by N,

b) is a 1,4-cyclohexylene radical, in which one or two non-adjacent CH₂groups can be replaced by --O-- or --S--,

c) is a 1,4-cyclohexenylene, piperidine-1,4-diyl,1,4-bicyclo[2.2.2]octylene or naphthalene-2,6-diyl radical,

where the radicals a) and b) can be monosubstituted or polysubstitutedby halogen atoms or cyano and/or methyl groups,

Z¹ is --CH₂ CH₂ --, --CO--O--, --O--CO--, --CH═CH--, --OCH₂ --, --CH₂O--, --C.tbd.C--, --(CH₂)₄ --, --CH═CH--CH₂ CH₂ -- or a single bond,

X is alkyl or alkoxy having 1 to 12 carbon atoms, NCS or Q--Y, where Qis --O--, --S-- or a single bond, and Y is CN, F, Cl or halogenatedalkyl or alkenyl having 1 to 5 carbon atoms,

L¹ and L² are each, independently of one another, H or F,

m is 0, 1 or 2, and

n is 0, 1 or 2, where m+n≧1,

with the proviso that, in the case where m=1, n=0 and X=alkyl, alkoxy,F, Cl or CN, L¹ and L² are fluorine.

The invention furthermore relates to the use of these compounds ascomponents of liquid-crystalline media and to liquid-crystal andelectro-optical display elements containing the liquid-crystalline mediaaccording to the invention.

The compounds of the formula I can be used as components ofliquid-crystalline media, in particular for displays based on theprinciple of the twisted cell, including highly twisted variantsthereof, such as, for example, STN or SBE, the guest-host effect, theeffect of deformation of aligned phases or the effect of dynamicscattering, in particular from matrix liquid-crystal displays (MLCdisplays).

The invention had the object of finding novel, stable,liquid-crystalline or mesogenic compounds which are suitable ascomponents of liquid-crystalline media and in particular havecomparatively low viscosity and high positive dielectric anisotropy.

Compounds of the formula ##STR3## are disclosed in J0 5310616.

It has now been found that compounds of the formula I are eminentlysuitable as components of liquid-crystalline phases. In particular, theyhave comparatively low viscosities. They can be used to obtain stableliquid-crystalline phases having a broad mesophase range advantageousvalues for the optical and dielectric anisotropy, which are at the sametime distinguished by very favorable values for the resistivity.Significant advantages can thus be achieved, in particular in the caseof media for matrix liquid-crystal displays (MLC displays) or Supertwistdisplays.

In addition, the provision of compounds of the formula I very generallyconsiderably broadens the range of liquid-crystalline substances whichare suitable, from various application points of view, for thepreparation of liquid-crystalline mixtures.

The compounds of the formula I have a broad range of applications.Depending on the chosen substituents, these compounds can be used asbase materials from which liquid-crystalline phases are predominantlycomposed; however, it is also possible to add compounds of the formula Ito liquid-crystalline base materials from other classes of compound inorder, for example, to modify the dielectric and/or optical anisotropyof the dielectric of this type and/or to optimize its threshold voltageand/or its viscosity and/or resistivity.

In the pure state, the compounds of the formula I are colorless and formliquid-crystalline mesophases in a temperature range which is favorablylocated for electro-optical use. They are stable chemically, thermallyand to light.

The invention thus relates to the compounds of the formula I, inparticular the compounds of the formula I in which n+m=2 and/or L¹ andL² are F.

The invention furthermore relates to the use of these compounds ascomponents of liquid-crystalline media.

The invention furthermore relates to liquid-crystalline media containingat least one compound of the formula I and to liquid-crystal displayelements, in particular electro-optical display elements, in particularmatrix liquid-crystal displays, containing media of this type.

For reasons of simplicity, A² below denotes ##STR4## Cyc denotes a1,4-cyclohexylene or 1,4-cyclohexenylene radical, Dio denotes a1,3-dioxane-2,5-diyl radical, Dit denotes a 1,3-dithiane-2,5-diylradical, Phe denotes a 1,4-phenylene radical, Pyd denotes apyridine-2,5-diyl radical, Pyr denotes a pyrimidine-2,5-diyl radical andBi denotes a bicyclo(2,2,2)octylene radical, where Cyc and/or Phe can beunsubstituted or monosubstituted or disubstituted by F or CN.

Accordingly, the compounds of the formula I include bicyclic ortricyclic compounds of the sub-formulae Ia to Ip:

    R--A.sup.2 --Phe--X                                        Ia

    R--Cyc--A.sup.2 --Phe--X                                   Ib

    R--Phe--A.sup.2 --Phe--X                                   Ic

    R--Dio--A.sup.2 --Phe--X                                   Id

    R--Dit--A.sup.2 --Phe--X                                   Ie

    R--Pyd--A.sup.2 --Phe--X                                   If

    R--Pyr--A.sup.2 --Phe--X                                   Ig

    R--Bi--A.sup.2 --Phe--X                                    Ih

    R--A.sup.2 --Phe--Phe--X                                   Ii

    R--Phe--Z.sup.1 --A.sup.2 --Phe--X                         Ij

    R--Cyc--Z.sup.1 --A.sup.2 --Phe--X                         Ik

    R--Dio--Z.sup.1 --A.sup.2 --Phe--X                         Il

    R--Dit--Z.sup.1 --A.sup.2 --Phe--X                         Im

    R--Pyd--Z.sup.1 --A.sup.2 --Phe--X                         In

    R--Pyr--Z.sup.1 --A.sup.2 --Phe--X                         Io

    R--Bi--Z.sup.1 --A.sup.2 --Phe--X                          Ip

tetracyclic compounds of the sub-formulae Iq-Iu:

    R--A.sup.1 --A.sup.1 --A.sup.2 --Phe--X                    Iq

    R--A.sup.1 --Z.sup.1 --A.sup.1 --A.sup.2 --Phe--X          Ir

    R--A.sup.1 --Z.sup.1 --A.sup.1 --Z.sup.1 --A.sup.2 --Phe--XIs

    R--A.sup.1 --A.sup.2 --Phe--Phe--X                         It

    R--A.sup.1 --Z.sup.1 --A.sup.2 --Phe--Phe--X               Iu

In the compounds of the sub-formulae Ia to Iu which contain one or morebridges Z¹, the bridging members are preferably --CH₂ CH₂ --, --CO--O--,--O--CO--, --CH₂ O--, --OCH₂ -- or --C.tbd.C--, in particular --CH₂ CH₂--.

R is preferably a straight-chain alkyl, furthermore alkoxy and alkenyl.

The compounds of the formula I preferably contain not more than one ofthe radicals Bi, Pyd, Pyr, Dio or Dit.

Particularly preferred compounds are the fluorocyclohexene derivativesof the formulae I1 to I39: ##STR5##

In the compounds of the formula I, X is preferably CN, NCS, OCN, F, Cl,CF₃, OCF₃, CF₂ H, CHF₂, CF₂ Cl, OCF₂ H, OCF₂ Cl, OCH₂ CF₃, OCHFCF₃, OCF₂CF₃, OCH₂ CF₂ H, OCH═CF₂, OCF═CF₂, OCF═CCl₂, OCH₂ C₂ Cl, CH₂ CF₃, CH₂CF₂ H, OCF═CH₂, CH═CF₂, CF═CF₂, CF═CH₂, OCH₃ or C₂ H₅.

Particular preference is given to compounds in which X is F, Cl, CN,OCF₃, OCHFCF₃, OCHF₂, OCH₂ CF₃, OCF═CF₂ or OCH═CF₂.

Preference is also given to compounds of the formula I in which the1,4-phenylene rings present in the molecule are monosubstituted ordisubstituted by fluorine. These are, in particular,2-fluoro-1,4-phenylene and 2,6-difluoro-1,4-phenylene.

If R is an alkyl radical or an alkoxy radical, this can bestraight-chain or branched. It is preferably straight-chain, has 2, 3,4, 5, 6 or 7 carbon atoms and accordingly is preferably ethyl, propyl,butyl, pentyl, hexyl, heptyl, ethoxy, propoxy, butoxy, pentoxy, hexoxyor heptoxy, furthermore methyl, octyl, nonyl, decyl, undecyl, dodecyl,tridecyl, tetradecyl, pentadecyl, methoxy, octoxy, nonoxy, decoxy,undecoxy, dodecoxy, tridecoxy or tetradecoxy.

Oxaalkyl is preferably straight-chain 2-oxapropyl (=methoxymethyl),2-oxabutyl (=ethoxymethyl) or 3-oxabutyl (=2-methoxyethyl), 2-, 3- or4-oxapentyl, 2-, 3-, 4- or 5-oxahexyl, 2-, 3-, 4-, 5- or 6-oxaheptyl,2-, 3-, 4-, 5-, 6 or 7-oxaoctyl, 2-, 3-, 5-, 6-, 7- or 8-oxanonyl, or2-, 3-, 4-, 5-, 6-, 7-, 8 or 9-oxadecyl.

If R is an alkenyl radical, this can be straight-chain or branched. Itis preferably straight-chain and has 2 to 10 carbon atoms. Accordingly,it is in particular vinyl, prop-1-, or prop-2-enyl, but-1-, 2- orbut-3-enyl, pent-1-, 2-, 3- or pent-4-enyl, hex-1-, 2-, 3-, 4- orhex-5-enyl, hept-1-, 2-, 3-, 4-, 5-or hept-6-enyl, oct-1-, 2-, 3-, 4-,5-, 6- or oct-7-enyl, non-1-, 2-, 3-, 4-, 5-, 6-, 7- or non-8-enyl, anddec-1-, 2-, 3-, 4-, 5-, 6-, 7-, 8- or dec-9-enyl.

If R is an alkyl radical in which one CH₂ group has been replaced by--O-- and one has been replaced by --CO--, these are preferablyadjacent. These thus contain an acyloxy group --CO--O-- or anoxycarbonyl group --O--CO--. These are preferably straight-chain andhave 2 to 6 carbon atoms. Accordingly, they are, in particular,acetyloxy, propionyloxy, butyryloxy, pentanoyloxy, hexanoyloxy,acetyloxymethyl, propionyloxymethyl, butyryloxymethyl,pentanoyloxymethyl, 2-acetyloxyethyl, 2-propionyloxyethyl,2-butyryloxyethyl, 3-acetyloxypropyl, 3-propionyloxylpropyl,4-acetyloxybutyl, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl,butoxycarbonyl, pentoxycarbonyl, methoxycarbonylmethyl,ethoxycarbonylmethyl, propoxycarbonylmethyl, butoxycarbonylmethyl,2-(methoxycarbonyl)ethyl, 2-(ethoxycarbonyl)ethyl,2-propoxycarbonyl)ethyl, 3-(methoxycarbonyl)propyl,3-(ethoxycarbonyl)propyl or 4-(methoxycarbonyl)butyl.

If R is an alkenyl radical in which one CH₂ group has been replaced byCO or CO--O or O--CO--, this can be straight-chain or branched. It ispreferably straight-chain and has 4 to 13 carbon atoms. Accordingly, itis, in particular, acryloyloxymethyl, 2-acryloyloxyethyl,3-acryloyloxypropyl, 4-acryloyloxybutyl, 5-acryloyloxypentyl,6-acryloyloxyhexyl, 7-acryloyloxyheptyl, 8-acryloyloxyoctyl,9-acryloyloxynonyl, 10-acryloyloxydecyl, methacryloyloxymethyl,2-methacryloyloxyethyl, 3-methacryloyloxypropyl, 4-methacryloyloxybutyl,5-methacryloyloxypentyl, 6-methacryloyloxyhexyl,7-methacryloyloxyheptyl, 8-methacryloyloxyoctyl or9-methacryloyloxynonyl.

Compounds of the formula I which contain wing groups R which aresuitable for polymerization reactions are suitable for the preparationof liquid-crystalline polymers.

Compounds of the formula I containing branched wing groups R mayoccasionally be of importance due to better solubility in theconventional liquid-crystalline base materials, but in particular aschiral dopes if they are optically active. Smectic compounds of thistype are suitable as components of ferroelectric materials.

Compounds of the formula I having S_(A) phases are suitable, forexample, for thermally addressed displays.

Branched groups of this type generally contain not more than one chainbranch. Preferred branched radicals R are isopropyl, 2-butyl(=1-methylpropyl), isobutyl (=2-methylpropyl), 2-methylbutyl, isopentyl(=3-methylbutyl), 2-methylpentyl, 3-methylpentyl, 2-ethylhexyl,2-propylpentyl, isopropoxy, 2-methylpropoxy, 2-methylbutoxy,3-methylbutoxy, 2-methylpentoxy, 3-methylpentoxy, 2-ethylhexoxy,1-methylhexoxy, 1-methylheptoxy, 2-oxa-3-methylbutyl,3-oxa-4-methylpentyl, 4-methylhexyl, 2-nonyl, 2-decyl, 2-dodecyl,6-methyloctoxy, 6-methyloctaroyloxy, 5-methylheptyloxycarbonyl,2-methylbutyryloxy, 3-methylvaleryloxy, 4-methylhexanoyloxy,2-chloropropionyloxy, 2-chloro-3-methylbutyryloxy,2-chloro-4-methylvaleryloxy, 2-chloro-3-methylvaleryloxy,2-methyl-3-oxapentyl or 2-methyl-3-oxahexyl.

If R is an alkyl radical in which two or more CH₂ groups have beenreplaced by --O-- and/or --CO--O--, this can be straight-chain orbranched. It is preferably branched and has 3 to 12 carbon atoms.Accordingly, it is, in particular, biscarboxymethyl,2,2-biscarboxyethyl, 3,3-biscarboxypropyl, 4,4-biscarboxybutyl,5,5-biscarboxypentyl, 6,6-biscarboxyhexyl, 7,7-biscarboxyheptyl,8,8-biscarboxyoctyl, 9,9-biscarboxynonyl, 10,10-biscarboxydecyl,bis(methoxycarbonyl)methyl, 2,2-bis(methoxycarbonyl)ethyl,3,3-bis(methoxycarbonyl)propyl, 4,4-bis(methoxycarbonyl)butyl,5,5-bis(methoxycarbonyl)pentyl, 6,6-bis(methoxycarbonyl)hexyl,7,7-bis(methoxycarbonyl)heptyl, 8,8-bis(methoxycarbonyl)octyl,bis(ethoxycarbonyl)methyl, 2,2-bis(ethoxycarbonyl)ethyl3,3-bis(ethoxycarbonyl)propyl, 4,4-bis(ethoxycarbonyl)butyl,5,5-bis(ethoxycarbonyl)hexyl.

Compounds of the formula I which contain wing groups R which aresuitable for polycondensations are suitable for preparation ofliquid-crystalline polycondensates.

The formula I covers the racemates of these compounds and the opticalantipodes, and mixtures thereof.

Of these compounds of the formula I and of the sub-formulae, preferenceis given to those in which at least one of the radicals present thereinhas one of the preferred meanings given.

In the compounds of the formula I, preferred stereoisomers are those inwhich the Cyc and piperidine rings are trans-1,4-disubstituted. Those ofthe abovementioned formulae which contain one or more groups Pyd, Pyrand/or Dio in each case include the two 2,5-positional isomers.

The 1,4-cyclohexenylene group preferably has the following structures:##STR6## The compounds of the formula I are prepared by methods knownper se, as described in the literature (for example in the standardworks, such as Houben-Weyl, Methoden der Organischen Chemie,Georg-Thieme-Verlag, Stuttgart), to be precise under reaction conditionswhich are known and are suitable for said reactions. Use can also bemade here of variants which are known per se, but are not mentioned herein greater detail.

The fluorocyclohexene derivatives of the formula I according to theinvention can be prepared, for example, as follows: ##STR7## Compoundsof the formulae II and III in which R, A¹, Z¹, L¹, L², X and m are asdefined in claim 1, and n is 1 or 2, are likewise a subject-matter ofthe invention.

The synthesis of some particularly preferred compounds is shown below ingreater detail: ##STR8## The liquid-crystalline media according to theinvention preferably contain 2 to 40, in particular 4 to 30, componentsas further constituents besides one or more compounds according to theinvention. These media very particularly preferably contain 7 to 25components besides one or more compounds according to the invention.These further constituents are preferably selected from nematic ornematogenic (monotropic or isotropic) substances, in particularsubstances from the classes of the azoxybenzenes, benzylideneanilines,biphenyls, terphenyls, phenyl or cyclohexyl benzoates, phenyl orcyclohexyl esters of cyclohexanecarboxylic acid, phenyl or cyclohexylesters of cyclohexylbenzoic acid, phenyl or cyclohexyl esters ofcyclohexylcyclohexanecarboxylic acid, cyclohexylphenyl esters of benzoicacid, of cyclohexanecarboxylic acid and ofcyclohexylcyclohexanecarboxylic acid, phenylcyclohexanes,cyclohexylbiphenyls, phenylcyclohexylcyclohexanes,cyclohexylcyclohexanes, cyclohexylcyclohexenes,cyclohexylcyclohexylcyclohexenes, 1,4-bis-cyclohexylbenzenes,4,4'-bis-cyclohexylbiphenyls, phenyl- or cyclohexylpyrimidines, phenyl-or cyclohexyl pyridines, phenyl- or cyclohexyldioxanes, phenyl- orcyclohexyl-1,3-dithianes, 1,2-diphenylethanes, 1,2-dicyclohexylethanes,1-phenyl-2-cyclohexylethanes,1-cyclohexyl-2-(4-phenylcyclohexyl)ethanes,1-cyclohexyl-2-biphenylylethanes, 1-phenyl-2-cyclohexylphenylethanes,optionally halogenated stilbenes, benzyl phenyl ethers, tolans andsubstituted cinnamic acids. The 1,4-phenylene groups in these compoundsmay also be fluorinated.

The most important compounds suitable as further constituents of mediaaccording to the invention can be characterized by the formulae 1, 2, 3,4 and 5:

    R'--L--E--R"                                               1

    R'--L--COO--E--R"                                          2

    R'--L--OOC--E--R"                                          3

    R'--L--CH.sub.2 CH.sub.2 --E--R"                           4

    R'--L--C.tbd.C--E--R"                                      5

In the formulae 1, 2, 3, 4 and 5, L and E, which may be identical ordifferent, are in each case, independently of one another, a bivalentradical from the group formed by --Phe--, --Cyc--, --Phe--Phe--,--Phe--Cyc--, --Cyc--Cyc--, --Pyr--, --Dio--, --G--Phe-- and --G--Cyc--and their mirror images, where Phe is unsubstituted orfluorine-substituted 1,4-phenylene, Cyc is trans-1,4-cyclohexylene or1,4-cyclohexenylene, Pyr is pyrimidine-2,5-diyl or pyridine-2,5-diyl,Dio is 1,3-dioxane-2,4-diyl and G is 2-(trans-1,4-cyclohexyl)ethyl,pyrimidine-2,5-diyl, pyridine-2,5-diyl or 1,3-dioxane-2,5-diyl.

One of the radicals L and E is preferably Cyc, Phe or Pyr. E ispreferably Cyc, Phe or Phe--Cyc. The media according to the inventionpreferably contain one or more components selected from the compounds ofthe formulae 1, 2, 3, 4 and 5 in which L and E are selected from thegroup consisting of Cyc, Phe and Pyr and simultaneously one or morecomponents selected from the compounds of the formulae 1, 2, 3, 4 and 5in which one of the radicals L and E is selected from the groupconsisting of Cyc, Phe and Pyr and the other radical is selected fromthe group consisting of --Phe--Phe--, --Phe--Cyc--, --Cyc--Cyc--,--G--Phe-- and --G--Cyc--, and optionally one or more componentsselected from the compounds of the formulae 1, 2, 3, 4 and 5 in whichthe radicals L and E are selected from the group consisting of--Phe--Cyc--, --Cyc--Cyc--, --G--Phe-- and --G--Cyc--.

In the compounds of the sub-formulae 1a, 2a, 3a, 4a and 5a, R' and R"are, in each case independently of one another, alkyl, alkenyl, alkoxy,alkenyloxy or alkanoyloxy having up to 8 carbon atoms. In most of thesecompounds, R' and R" are different from one another, one of theseradicals usually being alkyl or alkenyl. In the compounds of thesub-formulae 1b, 2b, 3b, 4b and 5b, R" is --CN, --CF₃, F, Cl or --NCS;in this case, R has the meaning given for the compounds of thesub-formulae 1a to 5a and is preferably alkyl or alkenyl. However, othervariants of the proposed substituents in the compounds of the formulae1, 2, 3, 4 and 5 are common. Many such substances or alternativelymixtures thereof are commercially available. All these substances can beobtained by methods which are known from the literature or analogouslythereto.

Besides components from the group consisting of the compounds 1a, 2a,3a, 4a and 5a (Group 1), the media according to the invention preferablyalso contain components from the group consisting of the compounds 1b,2b, 3b, 4b and 5b (Group 2), whose proportions are preferably asfollows:

Group 1: 20 to 90%, in particular 30 to 90%,

Group 2: 10 to 80%, in particular 10 to 50%,

the sum of the proportions of the compounds according to the inventionand of the compounds from Groups 1 and 2 adding up to 100%.

The media according to the invention preferably contain 1 to 40%, inparticular preferably 5 to 30%, of compounds according to the invention.Further preferred media are those which contain more than 40%, inparticular 45 to 90%, of compounds according to the invention. The mediapreferably contain three, four or five compounds according to theinvention.

The media according to the invention are prepared in a manner which iscustomary per se. In general, the components are dissolved in oneanother, expediently at elevated temperature. By means of suitableadditives, the liquid-crystalline phases can be modified in accordancewith the invention in a manner such that they can be used in all typesof liquid-crystal display elements which have hitherto been disclosed.Additives of this type are known to those skilled in the art and aredescribed in detail in the literature (H. Kelker/R. Hatz, Handbook ofLiquid Crystals, Verlag Chemie, Weinheim, 1980). For example, pleochroicdyes can be added for the production of colored guest-host systems, orsubstances can be added to modify the dielectric anisotropy, theviscosity and/or the orientation of the nematic phases.

The media according to the invention are particularly suitable for usein MLC displays.

In the present application and in the examples below, the structures ofthe liquid-crystal compounds are indicated by means of acronyms, thetransformation into chemical formulae taking place in accordance withTables A and B below. All radicals C_(n) H_(2n+1) and C_(m) H_(2m+1) arestraight-chain alkyl radicals having n or m carbon atoms respectively.

The coding in Table B is self-evident. In Table A, only the acronym forthe parent structure is given. In individual cases, the acronym for theparent structure is followed, separated by a dash, by a code for thesubstituents R¹, R², L¹ and L² :

    __________________________________________________________________________    Code for R.sup.1,                                                             R.sup.2, L.sup.1, L.sup.2                                                             R.sup.1         R.sup.2 L.sup.1                                                                          L.sup.2                                    __________________________________________________________________________    nm      CnH.sub.2n+1    C.sub.m H.sub.2m+1                                                                    H  H                                          nOm     C.sub.n H.sub.2n+1                                                                            OC.sub.m H.sub.2m+1                                                                   H  H                                          nO.m    OC.sub.n H.sub.2n+1                                                                           C.sub.m H.sub.2m+1                                                                    H  H                                          n       C.sub.n H.sub.2n+1                                                                            CN      H  H                                          nN.F    C.sub.n H.sub.2n+1                                                                            CN      H  F                                          nF      C.sub.n H.sub.2n+1                                                                            F       H  H                                          nOF     OC.sub.n H.sub.2n+1                                                                           F       H  H                                          nCl     C.sub.n H.sub.2n+1                                                                            Cl      H  H                                          nF.F    C.sub.n H.sub.2n+31                                                                           F       H  F                                          nF.F.F  C.sub.n H.sub.2n+31                                                                           F       F  H                                          nCF.sub.3                                                                             C.sub.n H.sub.2n+31                                                                           CF.sub.3                                                                              H  H                                          nOCF.sub.3                                                                            C.sub.n H.sub.2n+31                                                                           OCF.sub.3                                                                             H  H                                          nOCF.sub.2                                                                            C.sub.n H.sub.2n+31                                                                           OCHF.sub.2                                                                            H  H                                          nS      C.sub.n H.sub.2n+1                                                                            NCS     H  H                                          rVsN    C.sub.r H.sub.2r+1 --CH═CH--C.sub.s H.sub.2s --                                           CN      H  H                                          rEsN    C.sub.r H.sub.2r+1 --O--C.sub.2 H.sub.2s --                                                   CN      H  H                                          nAm     C.sub.n H.sub.2n+1                                                                            COOC.sub.m H.sub.2m+1                                                                 H  H                                          __________________________________________________________________________

                  TABLE A                                                         ______________________________________                                         ##STR9##                                                                      ##STR10##                                                                     ##STR11##                                                                     ##STR12##                                                                     ##STR13##                                                                     ##STR14##                                                                     ##STR15##                                                                     ##STR16##                                                                     ##STR17##                                                                     ##STR18##                                                                     ##STR19##                                                                     ##STR20##                                                                     ##STR21##                                                                     ##STR22##                                                                     ##STR23##                                                                     ##STR24##                                                                     ##STR25##                                                                     ##STR26##                                                                     ##STR27##                                                                     ##STR28##                                                                     ##STR29##                                                                     ##STR30##                                                                     ##STR31##                                                                     ##STR32##                                                                     ##STR33##                                                                    ______________________________________                                    

                  TABLE B                                                         ______________________________________                                         ##STR34##                                                                     ##STR35##                                                                     ##STR36##                                                                     ##STR37##                                                                     ##STR38##                                                                     ##STR39##                                                                     ##STR40##                                                                     ##STR41##                                                                     ##STR42##                                                                     ##STR43##                                                                     ##STR44##                                                                     ##STR45##                                                                     ##STR46##                                                                     ##STR47##                                                                     ##STR48##                                                                     ##STR49##                                                                     ##STR50##                                                                    ______________________________________                                    

The examples below are intended to illustrate the invention withoutrepresenting a limitation. Above and below, percentages are percent byweight. All temperatures are given in degrees Celsius. m.p.=meltingpoint, c.p.=clearing point. In addition, C=crystalline state, N=nematicstate, S=smectic phase and I=isotropic phase. The numbers between thesesymbols indicate the conversion temperature. Δn denotes opticalanisotropy (589 nm, 20° C.), and the viscosity (mm² /sec) was determinedat 20° C.

"Customary work-up" means that water is added, the mixture is extractedwith dichloromethane, methyl tertbutyl ether or diethyl ether, theorganic phase is separated off, dried and evaporated, and the product ispurified by crystallization and/or chromatography.

    ______________________________________                                        DAST           diethylaminosulfur trifluoride                                 DCC            dicyclohexylcarbodiimide                                       DDQ            dichlorodicyanobenzoquinone                                    DIBALH         diisobutylaluminum hydride                                     DMSO           dimethyl sulfoxide                                             POT            potassium tertiary-butoxide                                    THF            tetrahydrofuran                                                pTsOH          p-toluenesulfonic acid                                         ______________________________________                                    

EXAMPLE 1 ##STR51## A few drops of bromine are added to a suspension of1 mol of magnesium turnings in 250 ml of THF. A solution of 1 mol of1-bromo-4-fluorobenzene in 250 ml of THF is subsequently added dropwisein portions. The mixture is refluxed for 1.5 hours, and 0.9 mol of4-trans-4-propylcyclohexylcyclohexanone in 500 ml of THF are addeddropwise to the Grignard reagent at the boiling temperature. The mixtureis refluxed for 1.5 hours, and 1.5 l of water and 200 ml of conc. HClare added at 30° C. The mixture is stirred for a further 1/4 hour, theorganic phase is separated off, the aqueous phase is extracted withmethyl tert-butyl ether, and the combined organic phases are subjectedto customary work-up. ##STR52## 0.2 mol of the cyclohexene derivativefrom 1a) are dissolved in 500 ml of THF, and 240 ml of BH₃. THF complexare added over the course of 0.5 hour at +2° C. The mixture is stirredat +2° C. for a further 1 hour, allowed to warm to room temperature andstirred for a further hour. After addition of 60 ml of ethanol, themixture is warmed to 30° C., and firstly 40 ml of 6N NaOH and then 80 mlof 30% H₂ O₂ are added. The mixture is refluxed for 2 hours, allowed tocool to room temperature and hydrolyzed. The aqueous phase is separatedoff, and the organic phase is diluted with 250 ml of methyl tert-butylether. The organic phase is washed with 5% NaHSO₃ solution and water anddried over Na₂ SO₄. The solvent is removed on a Rotavapor, and theresidue is recrystallized from n-hexane. ##STR53## 0.094 mol of thecyclohexanol derivative from b) are dissolved in 250 ml ofdichloromethane in a nitrogen atmosphere, and 0.14 mol of pyridiniumchlorochromate is added. The reaction mixture is refluxed for 2 hoursand evaporated. The residue is purified over an Al₂ O₃ /silica gelcolumn. ##STR54## The cyclohexanone derivative (0.02 mol) from c) in 20ml of dichloromethane is added at room temperature to 0.0382 mol of DASTin 15 ml of dichloromethane. The mixture is refluxed for 4 hours, andthe reaction solution is allowed to cool to room temperature overnight.The mixture is hydrolyzed with ice cooling and subsequently subjected tocustomary work-up: ##STR55## The product (0.01 mol) is, without furtherpurification, dissolved in 50 ml of THF, 0.03 mol of potassiumtert-butoxide is added, and the mixture is stirred for 11 hours at 50°C. in an N₂ atmosphere. The mixture is allowed to cool to roomtemperature, ice water and conc. HCl are added, and the mixture isextracted with methyl tert-butyl ether. The product is subsequentlysubjected to customary work-up. C 40 N 124.5 I; Δn=+0.106; Δε=6.76

The following compounds of the formula ##STR56## are preparedanalogously:

    __________________________________________________________________________          ##STR57##                                                                             ##STR58##                                                                            X      L.sup.1                                                                         L.sup.2                                         __________________________________________________________________________    C.sub.2 H.sub.5                                                                     ##STR59##                                                                             ##STR60##                                                                            F      H H                                               C.sub.2 H.sub.5                                                                     ##STR61##                                                                             ##STR62##                                                                            F      H F                                               C.sub.2 H.sub.5                                                                     ##STR63##                                                                             ##STR64##                                                                            F      F F                                               n-C.sub.3 H.sub.7                                                                   ##STR65##                                                                             ##STR66##                                                                            F      H F                                                                                ##STR67##                                    n-C.sub.3 H.sub.7                                                                   ##STR68##                                                                             ##STR69##                                                                            F      F F                                                                                ##STR70##                                    n-C.sub.5 H.sub.11                                                                  ##STR71##                                                                             ##STR72##                                                                            F      H H                                               n-C.sub.5 H.sub.11                                                                  ##STR73##                                                                             ##STR74##                                                                            F      H F                                               n-C.sub.5 H.sub.11                                                                  ##STR75##                                                                             ##STR76##                                                                            F      F F                                               n-C.sub.3 H.sub.7                                                                   ##STR77##                                                                             ##STR78##                                                                            Cl     H H                                               n-C.sub.3 H.sub.7                                                                   ##STR79##                                                                             ##STR80##                                                                            Cl     H F                                               n-C.sub.3 H.sub.7                                                                   ##STR81##                                                                             ##STR82##                                                                            Cl     F F                                               n-C.sub.5 H.sub.11                                                                  ##STR83##                                                                             ##STR84##                                                                            Cl     H H                                               n-C.sub.5 H.sub.11                                                                  ##STR85##                                                                             ##STR86##                                                                            Cl     H F                                               n-C.sub.5 H.sub.11                                                                  ##STR87##                                                                             ##STR88##                                                                            Cl     F F                                               n-C.sub.3 H.sub.7                                                                   ##STR89##                                                                             ##STR90##                                                                            CF.sub.3                                                                             H H                                               n-C.sub.3 H.sub.7                                                                   ##STR91##                                                                             ##STR92##                                                                            CF.sub.3                                                                             H F                                               n-C.sub.3 H.sub.7                                                                   ##STR93##                                                                             ##STR94##                                                                            CF.sub.3                                                                             F F                                               n-C.sub.5 H.sub.11                                                                  ##STR95##                                                                             ##STR96##                                                                            CF.sub.3                                                                             H H                                               n-C.sub.5 H.sub.11                                                                  ##STR97##                                                                             ##STR98##                                                                            CF.sub.3                                                                             H F                                               n-C.sub.5 H.sub.11                                                                  ##STR99##                                                                             ##STR100##                                                                           CF.sub.3                                                                             F F                                               C.sub.2 H.sub.5                                                                     ##STR101##                                                                            ##STR102##                                                                           OCF.sub.3                                                                            H H                                               C.sub.2 H.sub.5                                                                     ##STR103##                                                                            ##STR104##                                                                           OCF.sub.3                                                                            H F                                               C.sub.2 H.sub.5                                                                     ##STR105##                                                                            ##STR106##                                                                           OCF.sub.3                                                                            F F                                               n-C.sub.3 H.sub.7                                                                   ##STR107##                                                                            ##STR108##                                                                           OCF.sub.3                                                                            H H                                                                                ##STR109##                                   n-C.sub.3 H.sub.7                                                                   ##STR110##                                                                            ##STR111##                                                                           OCF.sub.3                                                                            H F                                                                                ##STR112##                                   n-C.sub.5 H.sub.11                                                                  ##STR113##                                                                            ##STR114##                                                                           OCF.sub.3                                                                            H H                                               n-C.sub.5 H.sub.11                                                                  ##STR115##                                                                            ##STR116##                                                                           OCF.sub.3                                                                            H F                                               n-C.sub.5 H.sub.11                                                                  ##STR117##                                                                            ##STR118##                                                                           OCF.sub.3                                                                            F F                                               C.sub.2 H.sub.5                                                                     ##STR119##                                                                            ##STR120##                                                                           OCHF.sub.2                                                                           H H                                               C.sub.2 H.sub.5                                                                     ##STR121##                                                                            ##STR122##                                                                           OCHF.sub.2                                                                           H F                                               C.sub.2 H.sub.5                                                                     ##STR123##                                                                            ##STR124##                                                                           OCHF.sub.2                                                                           F F                                               n-C.sub.3 H.sub.7                                                                   ##STR125##                                                                            ##STR126##                                                                           OCHF.sub.2                                                                           H H                                                                                ##STR127##                                   n-C.sub.3 H.sub.7                                                                   ##STR128##                                                                            ##STR129##                                                                           OCHF.sub.2                                                                           H F                                                                                ##STR130##                                   n-C.sub.3 H.sub.7                                                                   ##STR131##                                                                            ##STR132##                                                                           OCHF.sub.2                                                                           F F                                               n-C.sub.5 H.sub.11                                                                  ##STR133##                                                                            ##STR134##                                                                           OCHF.sub.2                                                                           H H                                               n-C.sub.5 H.sub.11                                                                  ##STR135##                                                                            ##STR136##                                                                           OCHF.sub.2                                                                           H F                                               n-C.sub.5 H.sub.11                                                                  ##STR137##                                                                            ##STR138##                                                                           OCHF.sub.2                                                                           F F                                               C.sub.2 H.sub.5                                                                     ##STR139##                                                                            ##STR140##                                                                           OCH.sub.2 CF.sub.3                                                                   H H                                               C.sub.2 H.sub.5                                                                     ##STR141##                                                                            ##STR142##                                                                           OCH.sub.2 CF.sub.3                                                                   H F                                               C.sub.2 H.sub.5                                                                     ##STR143##                                                                            ##STR144##                                                                           OCH.sub.2 CF.sub.3                                                                   F F                                               n-C.sub.3 H.sub.7                                                                   ##STR145##                                                                            ##STR146##                                                                           OCH.sub.2 CF.sub.3                                                                   H H                                               n-C.sub.3 H.sub.7                                                                   ##STR147##                                                                            ##STR148##                                                                           OCH.sub.2 CF.sub.3                                                                   H F                                               n-C.sub.3 H.sub.7                                                                   ##STR149##                                                                            ##STR150##                                                                           OCH.sub.2 CF.sub.3                                                                   F F                                               n-C.sub.5 H.sub.11                                                                  ##STR151##                                                                            ##STR152##                                                                           OCH.sub.2 CF.sub.3                                                                   H H                                               n-C.sub.5 H.sub.11                                                                  ##STR153##                                                                            ##STR154##                                                                           OCH.sub.2 CF.sub.3                                                                   H F                                               n-C.sub.5 H.sub.11                                                                  ##STR155##                                                                            ##STR156##                                                                           OCH.sub.2 CF.sub.3                                                                   F F                                               n-C.sub.3 H.sub.7                                                                   ##STR157##                                                                            ##STR158##                                                                           OCF.sub.2 CF.sub.3                                                                   H H                                               n-C.sub.3 H.sub.7                                                                   ##STR159##                                                                            ##STR160##                                                                           OCF.sub.2 CF.sub.3                                                                   H F                                               n-C.sub.3 H.sub.7                                                                   ##STR161##                                                                            ##STR162##                                                                           OCF.sub.2 CF.sub.3                                                                   F F                                               n-C.sub.5 H.sub.11                                                                  ##STR163##                                                                            ##STR164##                                                                           OCF.sub.2 CF.sub.3                                                                   H H                                               n-C.sub.5 H.sub.11                                                                  ##STR165##                                                                            ##STR166##                                                                           OCF.sub.2 CF.sub.3                                                                   H F                                               n-C.sub.5 H.sub.11                                                                  ##STR167##                                                                            ##STR168##                                                                           OCF.sub.2 CF.sub.3                                                                   F F                                               n-C.sub.3 H.sub.7                                                                   ##STR169##                                                                            ##STR170##                                                                           OCH.sub.2 CF.sub.2 H                                                                 H H                                               n-C.sub.3 H.sub.7                                                                   ##STR171##                                                                            ##STR172##                                                                           OCH.sub.2 CF.sub.2 H                                                                 H F                                               n-C.sub.3 H.sub.7                                                                   ##STR173##                                                                            ##STR174##                                                                           OCH.sub.2 CF.sub.2 H                                                                 F F                                               n-C.sub.5 H.sub.11                                                                  ##STR175##                                                                            ##STR176##                                                                           OCH.sub.2 CF.sub.2 H                                                                 H H                                               n-C.sub.5 H.sub.11                                                                  ##STR177##                                                                            ##STR178##                                                                           OCH.sub.2 CF.sub.2 H                                                                 H F                                               n-C.sub.5 H.sub.11                                                                  ##STR179##                                                                            ##STR180##                                                                           OCH.sub.2 CF.sub.2 H                                                                 F F                                               C.sub.2 H.sub.5                                                                     ##STR181##                                                                            ##STR182##                                                                           OCHCF.sub.2                                                                          H H                                               C.sub.2 H.sub.5                                                                     ##STR183##                                                                            ##STR184##                                                                           OCHCF.sub.2                                                                          H F                                               C.sub.2 H.sub.5                                                                     ##STR185##                                                                            ##STR186##                                                                           OCHCF.sub.2                                                                          F F                                               n-C.sub.3 H.sub.7                                                                   ##STR187##                                                                            ##STR188##                                                                           OCHCF.sub.2                                                                          H H                                               n-C.sub.3 H.sub.7                                                                   ##STR189##                                                                            ##STR190##                                                                           OCHCF.sub.2                                                                          H F                                               n-C.sub.3 H.sub.7                                                                   ##STR191##                                                                            ##STR192##                                                                           OCHCF.sub.2                                                                          F F                                               n-C.sub.5 H.sub.11                                                                  ##STR193##                                                                            ##STR194##                                                                           OCHCF.sub.2                                                                          H H                                               n-C.sub.5 H.sub.11                                                                  ##STR195##                                                                            ##STR196##                                                                           OCHCF.sub.2                                                                          H F                                               n-C.sub.5 H.sub.11                                                                  ##STR197##                                                                            ##STR198##                                                                           OCHCF.sub.2                                                                          F F                                               n-C.sub.3 H.sub.7                                                                   ##STR199##                                                                            ##STR200##                                                                           OCH.sub.2 C.sub.2 F.sub.5                                                            H H                                               n-C.sub.3 H.sub.7                                                                   ##STR201##                                                                            ##STR202##                                                                           OCH.sub.2 C.sub.2 F.sub.5                                                            H F                                               n-C.sub.3 H.sub.7                                                                   ##STR203##                                                                            ##STR204##                                                                           OCH.sub.2 C.sub.2 F.sub.5                                                            F F                                               n-C.sub.5 H.sub.11                                                                  ##STR205##                                                                            ##STR206##                                                                           OCHFCF.sub.3                                                                         H H                                               n-C.sub.5 H.sub.11                                                                  ##STR207##                                                                            ##STR208##                                                                           OCHFCF.sub.3                                                                         H F                                               n-C.sub.5 H.sub.11                                                                  ##STR209##                                                                            ##STR210##                                                                           OCHFCF.sub.3                                                                         F F                                               n-C.sub.3 H.sub.7                                                                   ##STR211##                                                                            ##STR212##                                                                           CN     H H                                                                                ##STR213##                                   n-C.sub.3 H.sub.7                                                                   ##STR214##                                                                            ##STR215##                                                                           CN     H F                                               n-C.sub.3 H.sub.7                                                                   ##STR216##                                                                            ##STR217##                                                                           CN     F F                                               n-C.sub.5 H.sub.11                                                                  ##STR218##                                                                            ##STR219##                                                                           CN     H H                                               n-C.sub.5 H.sub.11                                                                  ##STR220##                                                                            ##STR221##                                                                           CN     H F                                               n-C.sub.5 H.sub.11                                                                  ##STR222##                                                                            ##STR223##                                                                           CN     F F                                               n-C.sub.3 H.sub.7                                                                   ##STR224##                                                                            ##STR225##                                                                           C.sub.2 H.sub.5                                                                      H H                                               n-C.sub.3 H.sub.7                                                                   ##STR226##                                                                            ##STR227##                                                                           C.sub.2 H.sub.5                                                                      H F                                               n-C.sub.3 H.sub.7                                                                   ##STR228##                                                                            ##STR229##                                                                           C.sub.2 H.sub.5                                                                      F F                                               n-C.sub.5 H.sub.11                                                                  ##STR230##                                                                            ##STR231##                                                                           n-C.sub.3 H.sub.7                                                                    H H                                               n-C.sub.5 H.sub.11                                                                  ##STR232##                                                                            ##STR233##                                                                           n-C.sub.3 H.sub.7                                                                    H F                                               n-C.sub.5 H.sub.11                                                                  ##STR234##                                                                            ##STR235##                                                                           n-C.sub.3 H.sub.7                                                                    F F                                               n-C.sub.3 H.sub.7                                                                   ##STR236##                                                                            ##STR237##                                                                           OCH.sub.3                                                                            H H                                               n-C.sub.3 H.sub.7                                                                   ##STR238##                                                                            ##STR239##                                                                           OCH.sub.3                                                                            H F                                               n-C.sub.3 H.sub.7                                                                   ##STR240##                                                                            ##STR241##                                                                           OCH.sub.3                                                                            F F                                               n-C.sub.5 H.sub.11                                                                  ##STR242##                                                                            ##STR243##                                                                           OC.sub.2 H.sub.5                                                                     H H                                               n-C.sub.5 H.sub.11                                                                  ##STR244##                                                                            ##STR245##                                                                           OC.sub.2 H.sub.5                                                                     H F                                               n-C.sub.5 H.sub.11                                                                  ##STR246##                                                                            ##STR247##                                                                           OC.sub.2 H.sub.5                                                                     F F                                               C.sub.2 H.sub.5                                                                     ##STR248##                                                                            ##STR249##                                                                           F      H H                                               C.sub.2 H.sub.5                                                                     ##STR250##                                                                            ##STR251##                                                                           F      H F                                               C.sub.2 H.sub.5                                                                     ##STR252##                                                                            ##STR253##                                                                           F      F F                                               C.sub.2 H.sub.5                                                                     ##STR254##                                                                            ##STR255##                                                                           F      H H                                               C.sub.2 H.sub.5                                                                     ##STR256##                                                                            ##STR257##                                                                           F      H F                                               C.sub.2 H.sub.5                                                                     ##STR258##                                                                            ##STR259##                                                                           F      F F                                               C.sub.2 H.sub.5                                                                     ##STR260##                                                                            ##STR261##                                                                           F      H H                                               C.sub.2 H.sub.5                                                                     ##STR262##                                                                            ##STR263##                                                                           F      H F                                               C.sub.2 H.sub.5                                                                     ##STR264##                                                                            ##STR265##                                                                           F      F F                                               n-C.sub.3 H.sub.7                                                                   ##STR266##                                                                            ##STR267##                                                                           F      H H                                               n-C.sub.3 H.sub.7                                                                   ##STR268##                                                                            ##STR269##                                                                           F      H F                                               n-C.sub.3 H.sub.7                                                                   ##STR270##                                                                            ##STR271##                                                                           F      F F                                               n-C.sub.3 H.sub.7                                                                   ##STR272##                                                                            ##STR273##                                                                           F      H H                                               n-C.sub.3 H.sub.7                                                                   ##STR274##                                                                            ##STR275##                                                                           F      H F                                               n-C.sub.3 H.sub.7                                                                   ##STR276##                                                                            ##STR277##                                                                           F      F F                                               n-C.sub.3 H.sub.7                                                                   ##STR278##                                                                            ##STR279##                                                                           F      H H                                               n-C.sub.3 H.sub.7                                                                   ##STR280##                                                                            ##STR281##                                                                           F      H F                                               n-C.sub.3 H.sub.7                                                                   ##STR282##                                                                            ##STR283##                                                                           F      F F                                               n-C.sub.5 H.sub.11                                                                  ##STR284##                                                                            ##STR285##                                                                           F      H H                                               n-C.sub.5 H.sub.11                                                                  ##STR286##                                                                            ##STR287##                                                                           F      H F                                                                                ##STR288##                                   n-C.sub.5 H.sub.11                                                                  ##STR289##                                                                            ##STR290##                                                                           F      F F                                               n-C.sub.5 H.sub.11                                                                  ##STR291##                                                                            ##STR292##                                                                           F      H H                                               n-C.sub.5 H.sub.11                                                                  ##STR293##                                                                            ##STR294##                                                                           F      H F                                               n-C.sub.5 H.sub.11                                                                  ##STR295##                                                                            ##STR296##                                                                           F      H H                                               n-C.sub.5 H.sub.11                                                                  ##STR297##                                                                            ##STR298##                                                                           F      H F                                               n-C.sub.5 H.sub.11                                                                  ##STR299##                                                                            ##STR300##                                                                           F      F F                                               n-C.sub.3 H.sub.7                                                                   ##STR301##                                                                            ##STR302##                                                                           Cl     H H                                               n-C.sub.3 H.sub.7                                                                   ##STR303##                                                                            ##STR304##                                                                           Cl     H F                                               n-C.sub.3 H.sub.7                                                                   ##STR305##                                                                            ##STR306##                                                                           Cl     F F                                               n-C.sub.3 H.sub.7                                                                   ##STR307##                                                                            ##STR308##                                                                           Cl     H H                                               n-C.sub.3 H.sub.7                                                                   ##STR309##                                                                            ##STR310##                                                                           Cl     H F                                               n-C.sub.3 H.sub.7                                                                   ##STR311##                                                                            ##STR312##                                                                           Cl     F F                                               n-C.sub.3 H.sub.7                                                                   ##STR313##                                                                            ##STR314##                                                                           Cl     H H                                               n-C.sub.3 H.sub.7                                                                   ##STR315##                                                                            ##STR316##                                                                           Cl     H F                                               n-C.sub.3 H.sub.7                                                                   ##STR317##                                                                            ##STR318##                                                                           Cl     F F                                               n-C.sub.3 H.sub.7                                                                   ##STR319##                                                                            ##STR320##                                                                           CF.sub.3                                                                             H H                                               n-C.sub.3 H.sub.7                                                                   ##STR321##                                                                            ##STR322##                                                                           CF.sub.3                                                                             H F                                               n-C.sub.3 H.sub.7                                                                   ##STR323##                                                                            ##STR324##                                                                           CF.sub.3                                                                             F F                                               n-C.sub.3 H.sub.7                                                                   ##STR325##                                                                            ##STR326##                                                                           CF.sub.3                                                                             H H                                               n-C.sub.3 H.sub.7                                                                   ##STR327##                                                                            ##STR328##                                                                           CF.sub.3                                                                             H F                                               n-C.sub.3 H.sub.7                                                                   ##STR329##                                                                            ##STR330##                                                                           CF.sub.3                                                                             F F                                               n-C.sub.3 H.sub.7                                                                   ##STR331##                                                                            ##STR332##                                                                           CF.sub.3                                                                             H H                                               n-C.sub.3 H.sub.7                                                                   ##STR333##                                                                            ##STR334##                                                                           CF.sub.3                                                                             H F                                               n-C.sub.3 H.sub.7                                                                   ##STR335##                                                                            ##STR336##                                                                           CF.sub.3                                                                             F F                                               n-C.sub.3 H.sub.7                                                                   ##STR337##                                                                            ##STR338##                                                                           OCF.sub.3                                                                            H H                                               n-C.sub.3 H.sub.7                                                                   ##STR339##                                                                            ##STR340##                                                                           OCF.sub.3                                                                            H F                                               n-C.sub.3 H.sub.7                                                                   ##STR341##                                                                            ##STR342##                                                                           OCF.sub.3                                                                            F F                                               n-C.sub.3 H.sub.7                                                                   ##STR343##                                                                            ##STR344##                                                                           OCF.sub.3                                                                            H H                                               n-C.sub.3 H.sub.7                                                                   ##STR345##                                                                            ##STR346##                                                                           OCF.sub.3                                                                            H F                                               n-C.sub.3 H.sub.7                                                                   ##STR347##                                                                            ##STR348##                                                                           OCF.sub.3                                                                            F F                                               n-C.sub.3 H.sub.7                                                                   ##STR349##                                                                            ##STR350##                                                                           OCF.sub.3                                                                            H H                                               n-C.sub.3 H.sub.7                                                                   ##STR351##                                                                            ##STR352##                                                                           OCF.sub.3                                                                            H F                                               n-C.sub.3 H.sub.7                                                                   ##STR353##                                                                            ##STR354##                                                                           OCF.sub.3                                                                            F F                                               n-C.sub.5 H.sub.11                                                                  ##STR355##                                                                            ##STR356##                                                                           OCF.sub.3                                                                            H H                                               n-C.sub.5 H.sub.11                                                                  ##STR357##                                                                            ##STR358##                                                                           OCF.sub.3                                                                            H F                                               n-C.sub.5 H.sub.11                                                                  ##STR359##                                                                            ##STR360##                                                                           OCF.sub.3                                                                            F F                                               n-C.sub.5 H.sub.11                                                                  ##STR361##                                                                            ##STR362##                                                                           OCF.sub.3                                                                            H H                                               n-C.sub.5 H.sub.11                                                                  ##STR363##                                                                            ##STR364##                                                                           OCF.sub.3                                                                            H F                                               n-C.sub.5 H.sub.11                                                                  ##STR365##                                                                            ##STR366##                                                                           OCF.sub.3                                                                            F F                                               n-C.sub.5 H.sub.11                                                                  ##STR367##                                                                            ##STR368##                                                                           OCF.sub.3                                                                            H H                                               n-C.sub.5 H.sub.11                                                                  ##STR369##                                                                            ##STR370##                                                                           OCF.sub.3                                                                            H F                                               n-C.sub.5 H.sub.11                                                                  ##STR371##                                                                            ##STR372##                                                                           OCF.sub.3                                                                            F F                                               n-C.sub.3 H.sub.7                                                                   ##STR373##                                                                            ##STR374##                                                                           OCHF.sub.2                                                                           H H                                               n-C.sub.3 H.sub.7                                                                   ##STR375##                                                                            ##STR376##                                                                           OCHF.sub.2                                                                           H F                                               n-C.sub.3 H.sub.7                                                                   ##STR377##                                                                            ##STR378##                                                                           OCHF.sub.2                                                                           F F                                               n-C.sub.3 H.sub.7                                                                   ##STR379##                                                                            ##STR380##                                                                           OCHF.sub.2                                                                           H H                                               n-C.sub.3 H.sub.7                                                                   ##STR381##                                                                            ##STR382##                                                                           OCHF.sub.2                                                                           H F                                               n-C.sub.3 H.sub.7                                                                   ##STR383##                                                                            ##STR384##                                                                           OCHF.sub.2                                                                           F F                                               n-C.sub.3 H.sub.7                                                                   ##STR385##                                                                            ##STR386##                                                                           OCHF.sub.2                                                                           H H                                               n-C.sub.3 H.sub.7                                                                   ##STR387##                                                                            ##STR388##                                                                           OCHF.sub.2                                                                           H F                                               n-C.sub.3 H.sub.7                                                                   ##STR389##                                                                            ##STR390##                                                                           OCHF.sub.2                                                                           F F                                               n-C.sub.5 H.sub.11                                                                  ##STR391##                                                                            ##STR392##                                                                           OCHF.sub.2                                                                           H H                                               n-C.sub.5 H.sub.11                                                                  ##STR393##                                                                            ##STR394##                                                                           OCHF.sub.2                                                                           H F                                               n-C.sub.5 H.sub.11                                                                  ##STR395##                                                                            ##STR396##                                                                           OCHF.sub.2                                                                           F F                                               n-C.sub.5 H.sub.11                                                                  ##STR397##                                                                            ##STR398##                                                                           OCHF.sub.2                                                                           H H                                               n-C.sub.5 H.sub.11                                                                  ##STR399##                                                                            ##STR400##                                                                           OCHF.sub.2                                                                           H F                                               n-C.sub.5 H.sub.11                                                                  ##STR401##                                                                            ##STR402##                                                                           OCHF.sub.2                                                                           F F                                               n-C.sub.5 H.sub.11                                                                  ##STR403##                                                                            ##STR404##                                                                           OCHF.sub.2                                                                           H H                                               n-C.sub.5 H.sub.11                                                                  ##STR405##                                                                            ##STR406##                                                                           OCHF.sub.2                                                                           H F                                               n-C.sub.5 H.sub.11                                                                  ##STR407##                                                                            ##STR408##                                                                           OCHF.sub.2                                                                           F F                                               n-C.sub.3 H.sub.7                                                                   ##STR409##                                                                            ##STR410##                                                                           OCH.sub.2 CF.sub.3                                                                   H H                                               n-C.sub.3 H.sub.7                                                                   ##STR411##                                                                            ##STR412##                                                                           OCH.sub.2 CF.sub.3                                                                   H F                                               n-C.sub.3 H.sub.7                                                                   ##STR413##                                                                            ##STR414##                                                                           OCH.sub.2 CF.sub.3                                                                   F F                                               n-C.sub.3 H.sub.7                                                                   ##STR415##                                                                            ##STR416##                                                                           OCH.sub.2 CF.sub.3                                                                   H H                                               n-C.sub.3 H.sub.7                                                                   ##STR417##                                                                            ##STR418##                                                                           OCH.sub.2 CF.sub.3                                                                   H F                                               n-C.sub.3 H.sub.7                                                                   ##STR419##                                                                            ##STR420##                                                                           OCH.sub.2 CF.sub.3                                                                   F F                                               n-C.sub.3 H.sub.7                                                                   ##STR421##                                                                            ##STR422##                                                                           OCH.sub.2 CF.sub.3                                                                   H H                                               n-C.sub.3 H.sub.7                                                                   ##STR423##                                                                            ##STR424##                                                                           OCH.sub.2 CF.sub.3                                                                   H F                                               n-C.sub.3 H.sub.7                                                                   ##STR425##                                                                            ##STR426##                                                                           OCH.sub.2 CF.sub.3                                                                   F F                                               n-C.sub.5 H.sub.11                                                                  ##STR427##                                                                            ##STR428##                                                                           OCH.sub.2 CF.sub.3                                                                   H H                                               n-C.sub.5 H.sub.11                                                                  ##STR429##                                                                            ##STR430##                                                                           OCH.sub.2 CF.sub.3                                                                   H F                                               n-C.sub.5 H.sub.11                                                                  ##STR431##                                                                            ##STR432##                                                                           OCH.sub.2 CF.sub.3                                                                   F F                                               n-C.sub.5 H.sub.11                                                                  ##STR433##                                                                            ##STR434##                                                                           OCH.sub.2 CF.sub.3                                                                   H H                                               n-C.sub.5 H.sub.11                                                                  ##STR435##                                                                            ##STR436##                                                                           OCH.sub.2 CF.sub.3                                                                   H F                                               n-C.sub.5 H.sub.11                                                                  ##STR437##                                                                            ##STR438##                                                                           OCH.sub.2 CF.sub.3                                                                   F F                                               n-C.sub.5 H.sub.11                                                                  ##STR439##                                                                            ##STR440##                                                                           OCH.sub.2 CF.sub.3                                                                   H H                                               n-C.sub.5 H.sub.11                                                                  ##STR441##                                                                            ##STR442##                                                                           OCH.sub.2 CF.sub.3                                                                   H F                                               n-C.sub.5 H.sub.11                                                                  ##STR443##                                                                            ##STR444##                                                                           OCH.sub.2 CF.sub.3                                                                   F F                                               n-C.sub.3 H.sub.7                                                                   ##STR445##                                                                            ##STR446##                                                                           OCF.sub.2 CF.sub.3                                                                   H H                                               n-C.sub.3 H.sub.7                                                                   ##STR447##                                                                            ##STR448##                                                                           OCF.sub.2 CF.sub.3                                                                   H F                                               n-C.sub.3 H.sub.7                                                                   ##STR449##                                                                            ##STR450##                                                                           OCF.sub.2 CF.sub.3                                                                   F F                                               n-C.sub.3 H.sub.7                                                                   ##STR451##                                                                            ##STR452##                                                                           OCF.sub.2 CF.sub.3                                                                   H H                                               n-C.sub.3 H.sub.7                                                                   ##STR453##                                                                            ##STR454##                                                                           OCF.sub.2 CF.sub.3                                                                   H F                                               n-C.sub.3 H.sub.7                                                                   ##STR455##                                                                            ##STR456##                                                                           OCF.sub.2 CF.sub.3                                                                   F F                                               n-C.sub.3 H.sub.7                                                                   ##STR457##                                                                            ##STR458##                                                                           OCF.sub.2 CF.sub.3                                                                   H H                                               n-C.sub.3 H.sub.7                                                                   ##STR459##                                                                            ##STR460##                                                                           OCF.sub.2 CF.sub.3                                                                   H F                                               n-C.sub.3 H.sub.7                                                                   ##STR461##                                                                            ##STR462##                                                                           OCF.sub.2 CF.sub.3                                                                   F F                                               n-C.sub.5 H.sub.11                                                                  ##STR463##                                                                            ##STR464##                                                                           OCF.sub.2 CF.sub.2 H                                                                 H H                                               n-C.sub.5 H.sub.11                                                                  ##STR465##                                                                            ##STR466##                                                                           OCF.sub.2 CF.sub.2 H                                                                 H F                                               n-C.sub.5 H.sub.11                                                                  ##STR467##                                                                            ##STR468##                                                                           OCF.sub.2 CF.sub.2 H                                                                 F F                                               n-C.sub.5 H.sub.11                                                                  ##STR469##                                                                            ##STR470##                                                                           OCF.sub.2 CF.sub.2 H                                                                 H H                                               n-C.sub.5 H.sub.11                                                                  ##STR471##                                                                            ##STR472##                                                                           OCF.sub.2 CF.sub.2 H                                                                 H F                                               n-C.sub.5 H.sub.11                                                                  ##STR473##                                                                            ##STR474##                                                                           OCF.sub.2 CF.sub.2 H                                                                 F F                                               n-C.sub.5 H.sub.11                                                                  ##STR475##                                                                            ##STR476##                                                                           OCF.sub.2 CF.sub.2 H                                                                 H H                                               n-C.sub.5 H.sub.11                                                                  ##STR477##                                                                            ##STR478##                                                                           OCF.sub.2 CF.sub.2 H                                                                 H F                                               n-C.sub.5 H.sub.11                                                                  ##STR479##                                                                            ##STR480##                                                                           OCF.sub.2 CF.sub.2 H                                                                 F F                                               n-C.sub.3 H.sub.7                                                                   ##STR481##                                                                            ##STR482##                                                                           OCHFCF.sub.3                                                                         H H                                               n-C.sub.3 H.sub.7                                                                   ##STR483##                                                                            ##STR484##                                                                           OCHFCF.sub.3                                                                         H F                                               n-C.sub.3 H.sub.7                                                                   ##STR485##                                                                            ##STR486##                                                                           OCHFCF.sub.3                                                                         F F                                               n-C.sub.3 H.sub.7                                                                   ##STR487##                                                                            ##STR488##                                                                           OCHFCF.sub.3                                                                         H H                                               n-C.sub.3 H.sub.7                                                                   ##STR489##                                                                            ##STR490##                                                                           OCHFCF.sub.3                                                                         H F                                               n-C.sub.3 H.sub.7                                                                   ##STR491##                                                                            ##STR492##                                                                           OCHFCF.sub.3                                                                         F F                                               n-C.sub.5 H.sub.11                                                                  ##STR493##                                                                            ##STR494##                                                                           OCH.sub.2 CF.sub.2 H                                                                 H H                                               n-C.sub.5 H.sub.11                                                                  ##STR495##                                                                            ##STR496##                                                                           OCH.sub.2 CF.sub.2 H                                                                 H F                                               n-C.sub.5 H.sub.11                                                                  ##STR497##                                                                            ##STR498##                                                                           OCH.sub.2 CF.sub.2 H                                                                 F F                                               n-C.sub.5 H.sub.11                                                                  ##STR499##                                                                            ##STR500##                                                                           OCH.sub.2 CF.sub.2 H                                                                 H H                                               n-C.sub.5 H.sub.11                                                                  ##STR501##                                                                            ##STR502##                                                                           OCH.sub.2 CF.sub.2 H                                                                 H F                                               n-C.sub.5 H.sub.11                                                                  ##STR503##                                                                            ##STR504##                                                                           OCH.sub.2 CF.sub.2 H                                                                 F F                                               n-C.sub.5 H.sub.11                                                                  ##STR505##                                                                            ##STR506##                                                                           OCH.sub.2 CF.sub.2 H                                                                 H H                                               n-C.sub.5 H.sub.11                                                                  ##STR507##                                                                            ##STR508##                                                                           OCH.sub.2 CF.sub.2 H                                                                 H F                                               n-C.sub.5 H.sub.11                                                                  ##STR509##                                                                            ##STR510##                                                                           OCH.sub.2 CF.sub.2 H                                                                 F F                                               n-C.sub.3 H.sub.7                                                                   ##STR511##                                                                            ##STR512##                                                                           OCHCF.sub.2                                                                          H H                                               n-C.sub.3 H.sub.7                                                                   ##STR513##                                                                            ##STR514##                                                                           OCHCF.sub.2                                                                          H F                                               n-C.sub.3 H.sub.7                                                                   ##STR515##                                                                            ##STR516##                                                                           OCHCF.sub.2                                                                          F F                                               n-C.sub.3 H.sub.7                                                                   ##STR517##                                                                            ##STR518##                                                                           OCHCF.sub.2                                                                          H H                                               n-C.sub.3 H.sub.7                                                                   ##STR519##                                                                            ##STR520##                                                                           OCHCF.sub.2                                                                          H F                                               n-C.sub.3 H.sub.7                                                                   ##STR521##                                                                            ##STR522##                                                                           OCHCF.sub.2                                                                          F F                                               n-C.sub.3 H.sub.7                                                                   ##STR523##                                                                            ##STR524##                                                                           OCHCF.sub.2                                                                          H H                                               n-C.sub.3 H.sub.7                                                                   ##STR525##                                                                            ##STR526##                                                                           OCHCF.sub.2                                                                          H F                                               n-C.sub.3 H.sub.7                                                                   ##STR527##                                                                            ##STR528##                                                                           OCHCF.sub.2                                                                          F F                                               n-C.sub.5 H.sub.11                                                                  ##STR529##                                                                            ##STR530##                                                                           OCHCF.sub.2                                                                          H H                                               n-C.sub.5 H.sub.11                                                                  ##STR531##                                                                            ##STR532##                                                                           OCHCF.sub.2                                                                          H F                                               n-C.sub.5 H.sub.11                                                                  ##STR533##                                                                            ##STR534##                                                                           OCHCF.sub.2                                                                          F F                                               n-C.sub.5 H.sub.11                                                                  ##STR535##                                                                            ##STR536##                                                                           OCHCF.sub.2                                                                          H H                                               n-C.sub.5 H.sub.11                                                                  ##STR537##                                                                            ##STR538##                                                                           OCHCF.sub.2                                                                          H F                                               n-C.sub.5 H.sub.11                                                                  ##STR539##                                                                            ##STR540##                                                                           OCHCF.sub.2                                                                          F F                                               n-C.sub.5 H.sub.11                                                                  ##STR541##                                                                            ##STR542##                                                                           OCHCF.sub.2                                                                          H H                                               n-C.sub.5 H.sub.11                                                                  ##STR543##                                                                            ##STR544##                                                                           OCHCF.sub.2                                                                          H F                                               n-C.sub.5 H.sub.11                                                                  ##STR545##                                                                            ##STR546##                                                                           OCHCF.sub.2                                                                          F F                                               n-C.sub.3 H.sub.7                                                                   ##STR547##                                                                            ##STR548##                                                                           OCHCF.sub.2                                                                          H H                                               n-C.sub.3 H.sub.7                                                                   ##STR549##                                                                            ##STR550##                                                                           OCHCF.sub.2                                                                          H F                                               n-C.sub.3 H.sub.7                                                                   ##STR551##                                                                            ##STR552##                                                                           OCHCF.sub.2                                                                          F F                                               n-C.sub.3 H.sub.7                                                                   ##STR553##                                                                            ##STR554##                                                                           OCHCF.sub.2                                                                          H H                                               n-C.sub.3 H.sub.7                                                                   ##STR555##                                                                            ##STR556##                                                                           OCHCF.sub.2                                                                          H F                                               n-C.sub.3 H.sub.7                                                                   ##STR557##                                                                            ##STR558##                                                                           OCHCF.sub.2                                                                          F F                                               n-C.sub.3 H.sub.7                                                                   ##STR559##                                                                            ##STR560##                                                                           OCHCF.sub.2                                                                          H H                                               n-C.sub.3 H.sub.7                                                                   ##STR561##                                                                            ##STR562##                                                                           OCHCF.sub.2                                                                          H F                                               n-C.sub.3 H.sub.7                                                                   ##STR563##                                                                            ##STR564##                                                                           OCHCF.sub.2                                                                          F F                                               n-C.sub.5 H.sub.11                                                                  ##STR565##                                                                            ##STR566##                                                                           OCHCF.sub.2                                                                          H H                                               n-C.sub.5 H.sub.11                                                                  ##STR567##                                                                            ##STR568##                                                                           OCHCF.sub.2                                                                          H F                                               n-C.sub.5 H.sub.11                                                                  ##STR569##                                                                            ##STR570##                                                                           OCHCF.sub.2                                                                          F F                                               n-C.sub.5 H.sub.11                                                                  ##STR571##                                                                            ##STR572##                                                                           OCHCF.sub.2                                                                          H H                                               n-C.sub.5 H.sub.11                                                                  ##STR573##                                                                            ##STR574##                                                                           OCHCF.sub.2                                                                          H F                                               n-C.sub.5 H.sub.11                                                                  ##STR575##                                                                            ##STR576##                                                                           OCHCF.sub.2                                                                          F F                                               n-C.sub.5 H.sub.11                                                                  ##STR577##                                                                            ##STR578##                                                                           OCHCF.sub.2                                                                          H H                                               n-C.sub.5 H.sub.11                                                                  ##STR579##                                                                            ##STR580##                                                                           OCHCF.sub.2                                                                          H F                                               n-C.sub.5 H.sub.11                                                                  ##STR581##                                                                            ##STR582##                                                                           OCHCF.sub.2                                                                          F F                                               n-C.sub.5 H.sub.11                                                                  ##STR583##                                                                            ##STR584##                                                                           OCH.sub.2 C.sub.2 F.sub.5                                                            H H                                               n-C.sub.5 H.sub.11                                                                  ##STR585##                                                                            ##STR586##                                                                           OCH.sub.2 C.sub.2 F.sub.5                                                            H F                                               n-C.sub.5 H.sub.11                                                                  ##STR587##                                                                            ##STR588##                                                                           OCH.sub.2 C.sub.2 F.sub.5                                                            F F                                               n-C.sub.5 H.sub.11                                                                  ##STR589##                                                                            ##STR590##                                                                           OCH.sub.2 C.sub.2 F.sub.5                                                            H H                                               n-C.sub.5 H.sub.11                                                                  ##STR591##                                                                            ##STR592##                                                                           OCH.sub.2 C.sub.2 F.sub.5                                                            H F                                               n-C.sub.5 H.sub.11                                                                  ##STR593##                                                                            ##STR594##                                                                           OCH.sub.2 C.sub.2 F.sub.5                                                            F F                                               n-C.sub.5 H.sub.11                                                                  ##STR595##                                                                            ##STR596##                                                                           OCH.sub.2 C.sub.2 F.sub.5                                                            H H                                               n-C.sub.5 H.sub.11                                                                  ##STR597##                                                                            ##STR598##                                                                           OCH.sub.2 C.sub.2 F.sub.5                                                            H F                                               n-C.sub.5 H.sub.11                                                                  ##STR599##                                                                            ##STR600##                                                                           OCH.sub.2 C.sub.2 F.sub.5                                                            F F                                               n-C.sub.5 H.sub.11                                                                  ##STR601##                                                                            ##STR602##                                                                           CN     H H                                               n-C.sub.5 H.sub.11                                                                  ##STR603##                                                                            ##STR604##                                                                           CN     H F                                               n-C.sub.5 H.sub.11                                                                  ##STR605##                                                                            ##STR606##                                                                           CN     F F                                               n-C.sub.5 H.sub.11                                                                  ##STR607##                                                                            ##STR608##                                                                           CN     H H                                               n-C.sub.5 H.sub.11                                                                  ##STR609##                                                                            ##STR610##                                                                           CN     H F                                               n-C.sub.5 H.sub.11                                                                  ##STR611##                                                                            ##STR612##                                                                           CN     F F                                               n-C.sub.5 H.sub.11                                                                  ##STR613##                                                                            ##STR614##                                                                           CN     H H                                               n-C.sub.5 H.sub.11                                                                  ##STR615##                                                                            ##STR616##                                                                           CN     H F                                               n-C.sub.5 H.sub.11                                                                  ##STR617##                                                                            ##STR618##                                                                           CN     F F                                               n-C.sub.3 H.sub.7                                                                   ##STR619##                                                                            ##STR620##                                                                           C.sub.2 H.sub.5                                                                      H H                                               n-C.sub.3 H.sub.7                                                                   ##STR621##                                                                            ##STR622##                                                                           C.sub.2 H.sub.5                                                                      H F                                               n-C.sub.3 H.sub.7                                                                   ##STR623##                                                                            ##STR624##                                                                           C.sub.2 H.sub.5                                                                      F F                                               n-C.sub.3 H.sub.7                                                                   ##STR625##                                                                            ##STR626##                                                                           C.sub.2 H.sub.5                                                                      H H                                               n-C.sub.3 H.sub.7                                                                   ##STR627##                                                                            ##STR628##                                                                           C.sub.2 H.sub.5                                                                      H F                                               n-C.sub.3 H.sub.7                                                                   ##STR629##                                                                            ##STR630##                                                                           C.sub.2 H.sub.5                                                                      F F                                               n-C.sub.3 H.sub.7                                                                   ##STR631##                                                                            ##STR632##                                                                           C.sub.2 H.sub.5                                                                      H H                                               n-C.sub.3 H.sub.7                                                                   ##STR633##                                                                            ##STR634##                                                                           C.sub.2 H.sub.5                                                                      H F                                               n-C.sub.3 H.sub.7                                                                   ##STR635##                                                                            ##STR636##                                                                           C.sub.2 H.sub.5                                                                      F F                                               n-C.sub.5 H.sub.11                                                                  ##STR637##                                                                            ##STR638##                                                                           n-C.sub.3 H.sub.7                                                                    H H                                               n-C.sub.5 H.sub.11                                                                  ##STR639##                                                                            ##STR640##                                                                           n-C.sub.3 H.sub.7                                                                    H F                                               n-C.sub.5 H.sub.11                                                                  ##STR641##                                                                            ##STR642##                                                                           n-C.sub.3 H.sub.7                                                                    F F                                               n-C.sub.5 H.sub.11                                                                  ##STR643##                                                                            ##STR644##                                                                           n-C.sub.3 H.sub.7                                                                    H H                                               n-C.sub.5 H.sub.11                                                                  ##STR645##                                                                            ##STR646##                                                                           n-C.sub.3 H.sub.7                                                                    H F                                               n-C.sub.5 H.sub.11                                                                  ##STR647##                                                                            ##STR648##                                                                           n-C.sub.3 H.sub.7                                                                    F F                                               n-C.sub.5 H.sub.11                                                                  ##STR649##                                                                            ##STR650##                                                                           n-C.sub.3 H.sub.7                                                                    H H                                               n-C.sub.5 H.sub.11                                                                  ##STR651##                                                                            ##STR652##                                                                           n-C.sub.3 H.sub.7                                                                    H F                                               n-C.sub.5 H.sub.11                                                                  ##STR653##                                                                            ##STR654##                                                                           n-C.sub.3 H.sub.7                                                                    F F                                               n-C.sub.3 H.sub.7                                                                   ##STR655##                                                                            ##STR656##                                                                           OCH.sub.3                                                                            H H                                               n-C.sub.3 H.sub.7                                                                   ##STR657##                                                                            ##STR658##                                                                           OCH.sub.3                                                                            H F                                               n-C.sub.3 H.sub.7                                                                   ##STR659##                                                                            ##STR660##                                                                           OCH.sub.3                                                                            F F                                               n-C.sub.3 H.sub.7                                                                   ##STR661##                                                                            ##STR662##                                                                           OCH.sub.3                                                                            H H                                               n-C.sub.3 H.sub.7                                                                   ##STR663##                                                                            ##STR664##                                                                           OCH.sub.3                                                                            H F                                               n-C.sub.3 H.sub.7                                                                   ##STR665##                                                                            ##STR666##                                                                           OCH.sub.3                                                                            F F                                               n-C.sub.3 H.sub.7                                                                   ##STR667##                                                                            ##STR668##                                                                           OCH.sub.3                                                                            H H                                               n-C.sub.3 H.sub.7                                                                   ##STR669##                                                                            ##STR670##                                                                           OCH.sub.3                                                                            H F                                               n-C.sub.3 H.sub.7                                                                   ##STR671##                                                                            ##STR672##                                                                           OCH.sub.3                                                                            F F                                               n-C.sub.5 H.sub.11                                                                  ##STR673##                                                                            ##STR674##                                                                           OC.sub.2 H.sub.5                                                                     H H                                               n-C.sub.5 H.sub.11                                                                  ##STR675##                                                                            ##STR676##                                                                           OC.sub.2 H.sub.5                                                                     H F                                               n-C.sub.5 H.sub.11                                                                  ##STR677##                                                                            ##STR678##                                                                           OC.sub.2 H.sub.5                                                                     F F                                               n-C.sub.5 H.sub.11                                                                  ##STR679##                                                                            ##STR680##                                                                           OC.sub.2 H.sub.5                                                                     H H                                               n-C.sub.5 H.sub.11                                                                  ##STR681##                                                                            ##STR682##                                                                           OC.sub.2 H.sub.5                                                                     H F                                               n-C.sub.5 H.sub.11                                                                  ##STR683##                                                                            ##STR684##                                                                           OC.sub.2 H.sub.5                                                                     F F                                               n-C.sub.5 H.sub.11                                                                  ##STR685##                                                                            ##STR686##                                                                           OC.sub.2 H.sub.5                                                                     H H                                               n-C.sub.5 H.sub.11                                                                  ##STR687##                                                                            ##STR688##                                                                           OC.sub.2 H.sub.5                                                                     H F                                               n-C.sub.5 H.sub.11                                                                  ##STR689##                                                                            ##STR690##                                                                           OC.sub.2 H.sub.5                                                                     F F                                               n-C.sub.3 H.sub.7                                                                   ##STR691##                                                                            ##STR692##                                                                           F      H H                                               n-C.sub.3 H.sub.7                                                                   ##STR693##                                                                            ##STR694##                                                                           F      H F                                                                                ##STR695##                                   n-C.sub.3 H.sub.7                                                                   ##STR696##                                                                            ##STR697##                                                                           F      F F                                               n-C.sub.5 H.sub.11                                                                  ##STR698##                                                                            ##STR699##                                                                           OCF.sub.3                                                                            H H                                               n-C.sub.5 H.sub.11                                                                  ##STR700##                                                                            ##STR701##                                                                           OCF.sub.3                                                                            H F                                               n-C.sub.5 H.sub.11                                                                  ##STR702##                                                                            ##STR703##                                                                           OCF.sub.3                                                                            F F                                               __________________________________________________________________________

EXAMPLE 2 ##STR704## Two drops of bromine are added to a suspension of0.25 mol of magnesium turnings in 60 ml of ether. A solution of 0.2 molof 3,5-difluoro-4-trifluoromethoxybromobenzene in 60 ml of ether issubsequently added dropwise. The mixture is stirred for a further 0.5hour, and a solution of 0.2 mol of4-trans-4-propylcyclohexylcyclohexanone in 50 ml of ether is then addeddropwise at 20°-25° C. to the Grignard reagent. The mixture is stirredfor a further 2 hours, poured into 500 ml of water, acidified andextracted by shaking with ether. The organic phase is evaporated todryness. The residue is dissolved in toluene and refluxed for 5 hourswith p-toluenesulfonic acid on a water separator. The mixture issubsequently cooled to room temperature, neutralized and is subjected tocustomary work-up. ##STR705## 0.2 mol of the cyclohexene derivative fromExample 1a) are dissolved in 200 ml of THF, and 0.2 g of sodiumborohydride is added. 0.24 mol of BF₃ etherate are added dropwise to themixture, during which the temperature of the reaction mixture should notexceed 10° C. The mixture is subsequently stirred at room temperaturefor a further 2 hours. After hydrolysis, the reaction mixture is treateddirectly, without further work-up, with a sulfuric acid solution ofsodium dichromate. During the oxidation, the reaction temperature shouldnot be higher than 15° C. The mixture is stirred for a further 1 hour atroom temperature and for a further 0.5 hour at 30° C. The mixture isfiltered, the filtrate is extracted with ether, the extract is washedwith water, and the solvent is removed in vacuo. The residue is purifiedby chromatography. ##STR706## 0.01 mol of the ketone from b) are treatedwith 0.025 mol of diethylaminosulfur trifluoride at 60° C. for 15 hours.The mixture is then introduced dropwise into ice water with stirring.After the addition of ether, the organic phase is separated off andsubjected to customary work-up. ##STR707## 13.5 mol of diisopropylamineare added dropwise at -20° C. to 13.5 mol of BuLi (15% in n-hexane) in10 ml of THF. The solution is subsequently stirred for 10 minutes andadded dropwise at -40° C. under a protective gas to a mixture comprising10 ml of THF and 13.5 mol of the geminal difluoro compound from c).

The mixture is stirred for 0.5 hour firstly at -40° C. and subsequentlyovernight at room temperature. After hydrolysis, the product issubjected to customary work-up.

We claim:
 1. A 2-Fluorocyclohexene compound of the formula I ##STR708##where R is an alkyl or alkenyl radical having 1 to 18 carbon atoms whichis unsubstituted or substituted by CN or by at least one halogen and inwhich one or more non-adjacent CH₂ groups can be replaced by a radicalselected from the group consisting of --O--, --S--, --CO--, --O--CO--,--CO--O-- and --C.tbd.C--,A¹ a) is a 1,4-phenylene radical, in which oneor two CH groups can be replaced by N, b) is a 1,4-cyclohexyleneradical, in which one or two non-adjacent CH₂ groups can be replaced by--O-- or --S--, c) is a 1,4-cyclohexenylene, piperidine-1,4-diyl,1,4-bicyclo[2.2.2]octylene or naphthalene-2,6-diyl radical, where theradicals a) and b) can be monosubstituted or polysubstituted by halogenatoms or cyano and/or methyl groups, Z¹ is --CH₂ CH₂ --, --CO--O--,--O--CO--, --CH═CH--, --OCH₂ --, --CH₂ O--, --C.tbd.C--, --(CH₂)₄ --,--CH═CH--CH₂ CH₂ -- or a single bond, X is alkyl or alkoxy having 1 to12 carbon atoms, NCS or Q--Y, where Q is --O--, --S-- or a single bond,and Y is CN, F, Cl or halogenated alkyl or alkenyl having 1 to 5 carbonatoms, L¹ and L² are each, independently of one another, H or F, m is 0,1 or 2, and n is 1 or
 2. 2. A 2-fluorocyclohexene compound of claim 1 ofthe formula ##STR709## in which R, X, L¹ and L² are as defined inclaim
 1. 3. A 2-fluorocyclohexene compound of claim 1 of the formula##STR710## in which R, X, L¹ and L² are as defined in claim
 1. 4. A2-fluorocyclohexene compound of claim 1 of the formula ##STR711## inwhich R, X, L¹ and L² are as defined in claim
 1. 5. A compound of theformula I of claim 1 in which L¹ and L² are fluorine.
 6. A compound ofthe formula I of claim 1 in which X is CN, F, Cl, OCF₃, OCHF₂, CF₃,OCHFCF₃, OCH₂ CF₃, OCH═CF₂ or OCF═CF₂.
 7. A compound of the formula I ofclaim 1 in which m+n=2.
 8. A fluid-crystalline medium having at leasttwo components, wherein at least one component is a compound of theformula I of claim
 1. 9. An electro-optical display element, comprising,as dielectric, a liquid-crystalline medium according to claim
 8. 10. Amatrix liquid-crystalline display element comprising, as dielectric, aliquid-crystalline medium according to claim
 8. 11. A compound accordingto claim 1, wherein A¹ is 1,4-cyclohexylene optionally mono- ordi-substituted by F or CN, 1,4-cyclohexenylene 1,3-dioxane-2,5-diyl,1,3-dithiane-2,5-diyl, 1,4-phenylene optionally mono- or di-substitutedby F or CN, pyridine-2,5-diyl or bicyclo(2,2,2)octylene.
 12. A compoundaccording to claim 1, wherein A¹ is 1,4-cyclohexylene or 1,4-phenylene.